My 2c on this topic... After a near-miss 8 years ago that would have lost all development data=20 I got a regular backup system in place, and another near-miss 5 years=20 ago when my shop got burgled I added online backups as well. I have a main monster work computer and a low-end laptop, and I want to=20 have backups and sync between them. Windows 7 on both. I have 5 directories I keep backed up: Development Email Media (pics) Random Documents Zips of software/drivers I commonly use (to make setting up a new laptop=20 faster, for example) Anything not in those directories I know is not going to be backed up=20 often. Total size: 30K files taking 47gb. "Treesize" is a good utility=20 for looking thru directory structures for unneeded stuff. I use "CopyTo synchronizer" to maintain sync between the lappy and the=20 desktop. I tell it which way to write, and off it goes. Handy. So I=20 tell it to write from desktop to the lappy, go work out of the house=20 when possible or @ client, and sync back at night. So my laptop and desktop are typically in sync within a few days. So=20 all data is now on 2 harddrives. I use "IDrive" to backup those directories online. I do this every few=20 days at most - daily when developing fast. So now it is all online as=20 well, and possible to retrieve earlier versions to some degree. Finally every several weeks, Norton Ghost does a backup of the main=20 computer's whole harddrive to another drive on the same machine. It=20 reminds me so that I don't forget to do it. So all the data is on 2 harddrives on main computer (main drive is 512gb=20 flash, actually), laptop harddrive, and online. This works pretty well... takes maybe 8 min to do the file sync between=20 computers, most of the time is scanning 30K files rather than the copy.=20 Of old work stuff that had many directories of many small files I made=20 a single .zip to speed it up. Not sure how much data the O.P. has, but the above would scale fine to=20 at least 5X the size since of course most of the data doesn't change.=20 The main thing is to not have zillions of small files (Eclipse IDE I'm=20 looking at you), if you can keep that under control you're set. Ok back to debugging I2C state machines J Harrison Cooper wrote: > There are several things that occur when it gets powered up, garbage > collection, etc so its not that you need to completely rewrite the > data, but simply accessing the device should suffice in restoring the > charge. As these get bigger in size, the technology shrinks and thus > the actual charge becomes smaller....smaller charge relates to not > lasting as long due to leakage. All I am saying is for any of these > technologies....tape, DVD, NAND, everything degrades in time. They > do make some DVD's that use a technology that is claimed to last a > very long time, but it takes a special writer to burn those. > > For me, I use an ISP that has 5-nines redundancy and ftp my archives > to their servers and cross my fingers... > > -----Original Message----- From: piclist-bounces@mit.edu > [mailto:piclist-bounces@mit.edu] On Behalf Of IVP Sent: Tuesday, > February 17, 2015 2:45 PM To: Microcontroller discussion list - > Public. Subject: Re: [PIC] SDHC read problem > >> let the controller refresh the charge > > Thanks, I didn't know that > > When you say "refresh the charge" do you mean just power it up or > actually re-write all the data ? > > That would be a pain and more hassle than copying a DVD every few > years > > Joe > > > ----- No virus found in this message. Checked by AVG - www.avg.com > Version: 2015.0.5646 / Virus Database: 4284/9133 - Release Date: > 02/17/15 > > -- http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > > ________________________________ > > PLEASE NOTE: The information contained in this electronic mail > message is intended only for the use of the designated recipient(s) > named above. If the reader of this message is not the intended > recipient, you are hereby notified that you have received this > message in error and that any review, dissemination, distribution, or > copying of this message is strictly prohibited. If you have received > this communication in error, please notify the sender by telephone or > e-mail (as shown above) immediately and destroy any and all copies of > this message in your possession (whether hard copies or > electronically stored copies). > > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .